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Carbon isotopes across the Eocene‐Oligocene boundary sequence of Kutch, western India: Implications to oceanic productivity and pCO 2 change
Author(s) -
Sarkar A.,
Sarangi S.,
Bhattacharya S. K.,
Ray A. K.
Publication year - 2003
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2002gl016541
Subject(s) - geology , extinction event , oceanography , productivity , isotopes of carbon , cenozoic , benthic zone , oceanic basin , total organic carbon , global cooling , climate change , weathering , carbon cycle , climatology , paleontology , structural basin , ecosystem , chemistry , ecology , environmental chemistry , biological dispersal , population , demography , sociology , biology , economics , macroeconomics
Analyses of foraminiferal δ 18 O (δ 18 O carb ), δ 13 C (δ 13 C carb ) and bulk organic matter (δ 13 C org ) across a tropical Eocene/Oligocene boundary (EOB) section from Kutch basin, western India show that the ocean cooling (at least ∼3°C) is coincident with a rapid enrichment (∼3‰) in δ 13 C org but depletion (∼1.5‰) in δ 13 C carb . The decrease in pCO 2 in ocean‐atmosphere system across the boundary, possibly resulting from enhanced silicate weathering in rising Himalayas and accompanied organic carbon burial in ocean, caused the cooling and δ 13 C org enrichment. The end‐Eocene climatic stress decreased the oceanic productivity (and δ 13 C carb ) eventually causing extinction of larger benthic foraminiferal community. The data suggest a critical role of tropical ocean and direct forcing of CO 2 on global climate change at least for this crucial Cenozoic transition.